Pump



A. RAPPL Oct. 5,l 1943..

PUMP

Filed May 7, 1941 i? f/ y Patented Oct. 5, 1943 PUMP Anton Rappl, Buialo, N. Y., assis-nor to Trico Products Corporation, Buffalo, N. Y.

Application May 7, 1941, Serial No. 392,297

('Cl. 230-l59) 14 Claims.

This invention relates to pumps and is particularly useful in the automotive eldin producing partial vacuum or differential fluid pressure for use in the operation of motor vehicle accessories, such as windshield cleaners.

Various forms of vane type' fluid pumps have heretofore been proposed, such pumps comprising essentially a casing and an oscillatable vane pivoted therein for alternate pumping movement in opposite directions. It has also been previously proposed to seal c ontacts of the vane with the walls of the casing by the use of a sealing lubricant. Various practical disadvantages have beenfound to exist in the pumping structures of the prior art by reason of shortcomings and inefficiencies in their method of sealing. The present invention is a modification of the construction shown in the co-pending application y of Erwin C. Horton and Anton Rappl, Serial No.

y 287,979, filed August 2, 1939, in which the present applicant'is' a joint inventor.

In my present invention I provide a pump structure with novel means for insuring a tight and efficient seal of the vane in its contact with the walls of the casing throughout such contact. The novel sealing action of the pump of my .invention results in a full sealing effect in places of contact where devices of the prior art have not provided a practically sufficient sealing arrangement.

. Further, according to my invention, the vane itself is of novel construction whereby the necessity for sealing of the vane against the Walls of the casing is materially reduced. This is brought about by a construction wherein the possibility of diffusion of differential fluid pressure in the pump is materially reduced. In other words the possible paths of fluid leak are reduced in number and increased in length, whereby the sealing requirements are lmaterially reduced, albeit the provisions for sealing exceed in effectiveness those of the prior art.

The novel arrangement of sealing means in my present invention is made with an eye to the practical considerations which construction of a pump of the subject type presents. Certain surfaces of the elements are muchmore difficult to produce with dead accuracy and in the construction herein proposed the required accuracy of such surfaces is relaxed somewhat by virtue of my novel sealing arrangement. Further practical advantages attendant upon construction and use of the pump of my invention will appear froma perusal of the ensuing description and the accompanying drawing.

the adjacent wall of the plate 4I I.

In the drawing:

Fig. 1 is a longitudinal cross-sectional view through my novel pump and in the form illustrated -such pump `is shown associated with a lubricant pressurepump, such as is conventionally used in internal combustion engines;

Fig. 2 is a transverse cross-sectional view taken through the casing on the line II-II of Fig. 1 with the movable portions in elevationl and partly broken away; and p Fig. 3 is a detailed elevational view of the vane of the pump of my invention viewed from the left as seen in Fig. 1. e

lThroughout the several figures of the drawing like characters of reference denote like parts andy the numeral I0 designates generally a cup-like casing which is adapted to be secured against a plate I I, as by means' of screws I2, to provide therebetween a pump chamber I3. A vane designated generally I 4 is disposed in the pump chamber I3 for oscillating movement therein about a pivot shaft I5 which is supported at its opposite ends in the cup-like casing and the plate II, respectively. In the illustrated form the casing I0 is cast with the pivot shaft in assembled position in the mold andthe shaft is suitably necked as shown in Fig. 1 to anchor it in accurately assembled position.

At the end of the vane I4 which is adjacent the pivot shaft I5- the vane is provided with an arcuate bearing portion I6 andthe adjacent wall of the casing is formed similarly arcuately as at Il. There is, however, no necessity for sealing between the vane portion I6 and the wall portion I1 of the casing at this point and ample clearance is provided as appears from a consideration of Fig. 2 of the drawing.

into intimate engagement with the surface of the stationary pivot shaft I5. Casting of the casing with the pivot shaft in situ produces a tight joint between the pivot shaft andthe wall portion I8.

At its opposite end, that is the end remote from the pivot shaft I5, the vane I4 is formed arcuately as at 20 and the wall of the casing III is similarly formed as at 2|, whereby the vane may travel along the wall portion 2| in sealing engagement upon oscillation of the vane I4.

The vane I4 is provided with fiat, parallel, end faces which engage respectively against the inner flat face of the cup-like casing I0 and against The vane I4 is formed with an intermediate opening 25 which in the illustrated form is oblong and preferably provided with flat side wall wear plates 26. A cam 21 fixed to a drive shaft 28 is disposed in the opening 25 and in the illustrated instance such cam may comprise merely a circular member fixed eccentrically to the drive shaft 28 whereby its rotation acts successively against the respective wear plates 28 to oscillate the vane I4 about the pivot shaft I5 in an obvious manner. The wear plates 26 may merely be disposed in recesses formed in the walls of the opening 25 without other securement, since the presence of the cam element 21 will serve effectively to prevent displacement of the plates 28 from their' recesses.

Referring to Fig. 1, the numeral 30 designates a nipple formed on the casing I\. to provide for connection of the pumping device with an accessory or other source from which fluid is to be withdrawn. 'I'he nipple 30 may be provided with any convenient conduit connecting means as, for instance, the gland nut 3| of Fig. 1, and

in the illustrated embodiment a strainer 32- is arranged in the pasage 33 which extends through the nipple 30. The passage 33 diverges into branches 34, see Fig. 2, which lead respectively to communication with the opposite sides of the casing through continuations 35 of thepassages 34. Check valves 36 in the passages 34 permit passage of fluid through the nipple to the conduits 34 and 35 and into the pumping chamber I3 at opposite sides of the vane I4 but prevent retrograde fluid flow through such passages. Opening movement of the ball check valves 36 is limited, stems 31 extending from screws 38 carried in the wall of the casing I0.

To provide for flow of fluid from the opposite side of the pump chamber I3, the vane I4 may be provided with a uid passage 48 extending from both faces of the vane I4 into communication with the cam opening 25. A pair of check valves 4I seat against annular rings 42 which are secured to the opposite faces of the vane I4 and provide valve seats for the valves 4I and also retain such valves in assembled position. Resilient means, in the present instance -in the form of a coil spring 44, is provided for normally urgingboth valves 4I into seated position. Fluid pressure against the outer faces of such valves displaces them from their seats and permits uid ow from the pump chamber into the cam opening 25. v I

The cam member 21 has a transverse opening 50 which establishes permanent communication between the opening 25 generally and the bore in the cam 21. which receives the drive shaft 28. The drive shaft 28 is in turn provided with an axial bore I whereby fluid passing through the transverse opening 50 in the cam element 21 traverses the opening 5I in the drive shaft 28 and subsequently is discharged from the drive shaft 28 through a transverse opening 52 therein.

In the form illustrated, the novel fluid pump of the present invention is shown associated with a lubricant pressure pump such as is conventionally provided in connection with the construction of internal combustion engines. Such pump may comprise a pair of intermeshing gears 54 and 55 or other rotary impelling members. In the illustrated embodiment the gear 54 is shown suported upon a stub shaft 56 for free rotation, the shaft 58 being supported in a casing 51 which cooperates with a face of the plate II to form a lubricant pumping chamber. The

other ofthe gears, 55, is xedly secured to the drive shaft 28 as by means of a key 59.

Means are provided for diverting a relatively small portion of the output lubricant of the lubricant pumping means for utilization in effectively sealing the fluid pumping unit comprising the vane I4 and the casing I8 against leakage around the vane. A passage 63 extends obliquely in the plate II whereby its inner end is in communication with a small bleed hole 64 which emerges from the surface of the plate II at the output pressure side of the lubricant pumping unit. The passage 63 communicates with an axial passage`65 formed in the pivot shaft I5 which in turn is provided with a transverse passage 51 which delivers lubricant under pressure to the several axially extending grooves 10 formed in the bearing portion I5 of the vane I4. From these grooves 1I) lubricant passes to the opposite end faces of the vane I4 as seen in Fig. 1 and, referring to the left end face as seen V' in Fig. 1, thence along grooves 12 formed in such face and shown in detail in Fig. 3. The grooves 12 communicate with grooves 13 formed in the arcuate face 20 of the vane I4 and in this way the sliding engagement of the face containing the grooves 12 as well as the arcuate face 20, against the walls of the casing III, is eifectively sealed against fluid escape.

. It will be noted that the opening 25 for cooperation with the cam element 21 does not extend completely through the vane I4 so that an end wall 15 is provided. For this reason there is no danger of direct escape of fluid pressure from the pump chamber I3 into the opening 25 at this side of the vane.

The provision of the wall 15 at theA face of the vane which is disposed in what may be referred to as the bottom of the cup-shaped casing IILisSgnicant and important for reasons which follow. The face of the plate II which serves as a wall of the pump is obviously easily produced in accurately flat form and the problem of sealing, as between s'uch face and the engaging face of the vane I4, is relatively simple. The cup-shaped casing III, however, is best produced by die-casting and such 'production is usually intended to substantially eliminate further machining and finishing operations thereon. In any event, to machine the inside bottom of such casing would be impracticable on a production scale. Yet in producing this part by die-casting slight warpage and inaccuracies are present, not of sutlicient degree to interfere with relatively smooth sliding of the face of the vane I4 thereagainst, but sufficient to render efficient sealing a more aggravating problem than, for instance, sealing of the vane I4 against the surface of the plate II.

I have found that by providing the wall portion 15lthe path necessary to be traversed by fluid seeking to escape from one side of the pump chamber- I3 to the other is made sufficiently long to substantially avoid such escape at this particular partof the device. Also, of course, the wall portion 15 positively prevents passage of fluid between the pump chamber I3 and the cam opening 25 at this point. The presence of the oil grooves 12 across this surface of the vane of course still further enhances the effectiveness of the fluid seal at this critical point in the pump.

Spent sealing lubricant which is discharged into the pumping chamber I3 is subsequently entrained with fluid being delivered therefrom and it will be noted that such fluid is delivered through the axial opening Il of the drive shaft 28 and, through the transverse passage 62, into the engine crank case.

While a single specific embodiment of the principles of my invention is set forth herein by way of example, it is to be understood that I do not intend to limit the scope of my invention thereto or otherwise than as defined in the appended claims.

What is claimed is:

1. A pump comprising a casing having a chamber and inlet and outlet means, a fluid displacing member and means pivotally supporting the same at an end thereof, said displacing member and said pivotal means cooperating to divide said chamber into pump compartments, the opposite end of said displacing member being arranged to slidabiy engage a wall of said chamber, said displacing member having an opening therein extending transversely to the direction of movement thereof, a member extending into said opening and movable therein to reciprocate said displacing member, said opening emerging from one face only of said member, and grooves cooperating with the opposite `face thereof and with the wall of said casing.to form fluid conduits extending from a source of lubricant under pressure, said conduits extending to said opposite end of said displacing member and across the face thereof to effectively seal said face against fluid leak and passagey means for introducing lubricant to said grooves.

2. A pump comprising a casing having a chamber and inlet and outlet means, a fluid displacing member dividing the same into pump compartments and movable to and fro therein for displacing fluid first from one side and then from the opposite side thereof, said displacing member having an opening therein extending transversely to the direction of movement thereof and a member extending into said opening and movable therein to move said displacing member to and fro, Said opening emerging from one face only of said displacin-g member, and grooves cooperating with the opposite face `thereof and with the wall of said casing to form fluid conduits extending from a source of lubricant. under pressure to distribute sealing fluid substantially throughout said face to seal the same against fluid leak and passage means for introducing lubricant to said grooves.

3. A pump comprising a casing having a chamversely to the direction of movement thereof and ber and inlet and outlet means, a fluid displacing member dividing the same into pump compartments and movable to and fro therein for displacing fluid first from one side and then lfrom the opposite side thereof, said displacing member having an opening therein extending transversely to the direction of movement thereof, and a cam Journaled in the casing and movable in the opening to move said member to and fro, said opening emerging from one face only of said displacing member, and grooves cooperating with the opposite face thereof and with the wall of said casing to form fluid conduits extending from a source of lubricant under pressure, said conduits extending to the extremity of said face of said member and terminating in grooves extending across an end of said member and passage means for introducing lubricant to said grooves.

4. A pump comprising a casing having a chamber and inlet and outlet means, a fluid displacing member dividing the same into pump compartments and movable to and fro therein for displacing fluid flrst from one side and then from a member extending into said opening and movable therein .to move said displacing member to and fro, said opening emerging from one face only of said displacing member, and grooves cooperating with the-opposite face thereof and with the wall of said casing to form fluid conduits extending from a source of lubricant under pressure, said conduits extending to the extremity of said face of said member and terminating in grooves extending across an end of said member and passage means for introducing lubricant to said grooves.

5. A pump comprising a. casing having a chamber and inlet and outlet means, a fluid displacing member and means pivotally supporting the same at an end thereof. said displacing member and said' pivotal means cooperating to divide said chamber into pump compartments, the

opposite end of said displacing member being arranged to slidabiy engage a wall of said chamber, said displacing member having an opening therein extending transverselytc the direction of movement thereof, and a cam journalled in the casing and movable in the opening to reciprocate said member, said opening emerging from one face only of said displacing member, and grooves cooperating with the opposite face thereof andwith the Wall of said casing to form fluid conduits extending from a source of lubricant under pressure, said conduits extending to said opposite end of said displacing member and across the face thereof to effectively seal'said face against fluid leak and passage means for introducing lubricant to said grooves.

6. A pump comprising a casing having a chamber and inlet and outlet means, a fluid displacing member dividing the same into pump compartments and movable to and fro thereiny for displacing fluid first from one side and then from the opposite side thereof, said displacing member having an opening extending transversely to the direction of movement thereof and a member extending into said opening and movable therein to move said. displacing member to and fro, a laterall face of said member being in permanent engagement with a Wall of said casing, and grooves cooperating with said wall and said lateral face to form fluid conduits extending from a source of lubricant under pressure to distribute sealing fluid substantially throughout said face to seal the same against fluid leak and passage means for introducing lubricant to said grooves.

7. A pump having a casing comprising a cuplike housing having a relatively flat inner wall and a circumferential flange, a cover plate seating thereover to form a chamber, pump inlet and outlet means, a fluid displacing member dividing the chamber into pump compartments and movable to and fro therein for displacing fluid first from one side and then from the opposite side thereof, said displacing member having an opening extending transversely to the direction of movement thereof and a member extending into said opening from said cover plate and movable to move said displacing member to and fro, said opening emerging only from the face of said displacing member which is contiguous with said cover plate, the opposite face of said member` being substantially continuous in extent and substantially flat for sliding engagement'with said flat inner wall of the cup-like housing.

8. A pump having a casing comprising a cuplike housing and a cover plate seating thereover to form a chamber, pump inlet and outlet means, a iiuid displacing member dividing the chamber into pump compartments and movable to and fro therein for displacing nuid first from one side and then from the opposite side thereof, said displacing member having an opening extending transversely to the direction of movement thereof and a member extending into said opening from said cover plate and movable to moveY said displacing member to and fro, said opening emerging only from the face of said displacing member which is contiguous with said cover plate,.

the opposite face of said member being substantially continuous in extent for sliding engagement with an interior wall of the cup-like housing, and grooves cooperating with said interior lwall and said opposite face to form fluid conduits extending from a source of lubricant under pressure to distribute sealing iluid substantially throughout said face to seal the same against fluid leak and passage means for introducing lubricant to said grooves.

9. A pump comprising a casing having a chamand inlet and outlet means, a iiuid displacing member having opposite flatface portions in sliding engagement with opposite interior walls of said casing to divide the chamber into pump compartments and movable to and fro therein for displacing fluid iirst from one side and then from -the opposite side thereof, said displacing member having an opening 'extending transversely to the direction of movement thereof and a member extending into said opening from an adjacent casing wall and movable in said opening to move said displacing member to and fro', said opening emerging from one iiat face portion of said displacing member, the opposite flat face of said member being substantially continuous in extent for sliding engagement with its associated casing wall.

10. A pump comprising a casing having a chamber and inlet and outlet means, a uid displacing member having opposite iiat face portions in sliding engagement with opposite interior Walls of said casing to divide the chamber into pump compartments and movable to and fro therein for displacing fluid iirst from one side and then from the opposite side thereof, said displacing member having an opening extending transversely to the direction of movement thereof and a member .extending into said opening from an adjacent casing wall and movable in said opening to move said displacing member to and fro, said opening emerging from one flat face portion of said displacing member, the opposite face of said member being substantially continuous in extent for sliding engagement with its associated casing wall, and grooves cooperating with said Wall and said opposite face to form uid conduits extending from a source of lubricant under pressure to distribute sealing fluid substantially throughout said face to seal the same against fluid leak and passage means for introducing lubricant to said grooves.

11. A pump comprising a casing having a chamber, a uid displacing member having opposite at face portions in sliding engagement with opposite flat interior walls of said casing to divide the chamber into pump compartments and movable to and fro therein for displacing fluid first from one side and then from the opposite side thereof, said pump having passage means for introducing fluid into said pump compartments and for discharging fluid therefrom, said displacing member having an opening extending transversely to the direction of movement thereof and a member extending into said opening from an adjacent casing wall and movable in said openi'ng to move said displacing member to and fro, said opening comprising a portion of said passage means and emerging from only one of said flat face portions of the displacing member, the opposite face thereof being substantially continuous in extent for sliding engagement with its associated casing wall.

12. A pump comprising a casing having a chamber, a fiuid displacing member having opposite fiat 'face portions in sliding engagement with opposite interior walls of said casing to divide the chamber into pump compartments and movable to and fro therein for displacing iiuid iirst from one side and then from the opposite side thereof, said pump having passage means for introducing fluid into said pump compartments and for discharging uid therefrom, said displacing member having an opening extending transversely to the direction of movement thereof and a .member extending into said opening from an adjacent casing wall and movable in said opening to move said displacing member to and fro, said opening comprising a portion of said passage means and emerging from only one of said flat face portions of the displacing member, the opposite face thereof being substantially continuous in extent for sliding engagement with its associated casing Wall, and grooves between said opposite face and said wall to form uid conduits extending from a source of lubricant under pressure to distribute sealing iiuid substantially throughout said face to seal the same against fluid leak and passage means for introducing lubricant to said grooves.

13. A pump comprising a casing having a chamber and inlet and outlet means, a iiuid displacing member and means pivotally supporting the same at an end thereof, said displacing member and said pivotal means cooperating to divide said chamber into pump compartments, the opposite end of said displacing member being arranged to slidably engage a Wall of said chamber, said displacing member having an opening extending transversely to the direction of movement thereof, and a member extending into said opening and movable therein to reciprocate said displacing member, said pivotal supporting means being adapted to introduce sealing lubricant to a face of said displacing member in engagement with the Wall of said chamber, and a groove extending from said pivotal means substantially to the opposite end of said displacing member for cooperation with said face of said displacing member and the contiguous casing wall to form a uid conduit to distribute sealing lubricant to said face of the displacing member to seal said face against fluid leak and passage means for introducing lubricant to said groove.

14. A pump comprising a casing having a chamber and inlet and outlet means, a uid displacing member and means pvotally supporting the same 'at an end thereof, said displacing member and said pivotal means cooperating to divide said chamber into pump compartments, the opposite end of said displacing member being arranged to slidably engage a Wall of said chamber, said displacing member having an opening eX- tending transversely to the direction of movement thereof, and a member extending into said opening and movable therein to reciprocate said said face of said displacing member and said wall oi' said chamber to form a iiuid conduit to conveyy sealing lubricant to said opposite end of said displacing member, said two grooves converging toward said opposite end of the displacing member.

` J ANTON RAPPL. 

